Lake Controls

Preset

Phosphorus loading 1.20 g/m²·yr Fish stocking (grazing) 1.00× Reaeration 1.00× Sim speed 1.0×

State

Phosphorus P—

Algae A—

Oxygen O—

Fish F—

Regime—

Days simulated0

Hysteresis area0.00

Phosphorus runoff feeds algae; algal death sucks oxygen from the water; fish suffocate below ~3 mg/L O₂. Past a threshold the lake "tips" into a turbid, anoxic state — and lowering loading again often will not reverse it. Drag the loading slider slowly up, then back down, and watch the phase plot trace a hysteresis loop.